Alastair MacAulay

WEST PALM BEACH, Fla. — No ballet by the 27-year-old choreographer Justin Peck is much like another; with each assignment he sets himself new choreographic hurdles. But Mr. Peck has quickly become the most eminent choreographer of ballet in the United States — and two particular characteristics have propelled him to the top: the exciting formal architecture of his dances and the kinesthetic thrill of his movement.